MLA

Ralf-Udo Ehlers, and Ralf-Udo Ehlers. Regulation of Biological Control Agents. Springer Netherlands, 2011.

APA

Ralf-Udo Ehlers, R. Ehlers, & Ehlers, R. (2011). Regulation of Biological Control Agents. Springer Netherlands.

Chicago

Ralf-Udo Ehlers, and Ralf-Udo Ehlers. Regulation of Biological Control Agents. : Springer Netherlands, 2011.